Increasing temporal variations in growth of Swedish forests call for better mechanistic insights

In recent decades, Swedish forests have experienced increasing variability of annual growth rate both in amplitude and frequency, jeopardizing national contribution to EU targets for carbon sequestration and climate change mitigation during periods of time. We postulate a set of hypotheses that with variable strengths can help explain and evaluate five major phases of growth variability observed the last three decades. We suggest that each phase needs to be understood based on its unique combinations of long-term monotonic trends and short-term extreme events, both that directly and indirectly influence growth rate. While the mechanistic understanding underlying this variability remains elusive, our set of hypotheses suggest that we need to move beyond traditional correlative approaches and instead combine observational data with process-based studies, large scale experiments, and modelling to will help support the development of adaptive management strategies to ensure forest resilience.